Water based drilling mud filtrate contamination monitoring is a large challenge in downhole formation water sampling. Currently, there are no conventional downhole real time methods available for quantitative water based drilling mud filtrate contamination monitoring during water sampling with the lone exception of using special dyes mixed with the water based drilling mud.
Use of special dyes adds complexity to drilling operations. Dyes added should be compatible with the drilling mud and the formation and fluids for the formation that are expected to be extracted. Some dyes can be expensive and additional work is required for injection of the dye into the fluid stream.
Special dyes are expensive for operators in other ways as operators need time to add the dye to wellbore mud systems as rig time can be very constrained. These special dyes, because of the complexities described above, are carefully crafted such that they provide minimal harm from a technological and cost perspective.